1. Field of the Art
The present invention relates in general to an electromagnetic levitation casting, and more particularly to a horizontal casting process of continuously casting a flat ingot, in particular, a thin strip, by utilizing electromagnetism to levitate a mass of molten metal introduced in a horizontal direction, in combination with a direct chilling operation to solidify the molten metal.
2. Related Art Statement
In recent years, a continuing casting process, so-called "horizontal continuous casting", wherein a tubular casting mold is adapted for horizontal casting of an ingot, has been extensively practiced in the industry, because of its relatively high productivity, taking the place of conventional semi-continuous vertical casting processes. This horizontal continuous casting process has been drawing increased attention in the industry. A typical example of a horizontal continuous casting system is disclosed in a Japanese Patent Application which was laid open in 1982 under Publication No. 57-139448. Described more specifically, the disclosed horizontal continuous casting system employs a tundish located on one side of a tubular horizontal casting mold. The tundish holds a mass of molten metal such as aluminum or its alloy. The molten metal accommodated in the tundish is supplied to the casting mold through an opening formed in a baffle plate. The casting mold is equipped with a water jacket surrounding the mold walls, so that cooling water circulating in the water jacket cools the mold walls, whereby the mass of the melt introduced in the casting mold is cooled via the mold walls and solidified into a solid ingot. The formed solid ingot is withdrawn continuously in the horizontal direction on a suitable table (roller), and by means of pinch rolls or other conveying equipment. To assure perfect solidification of the cast ingot emerging from the mold, the mold has a water channel which communicates with the water jacket and terminates in a nozzle, so that the cooling water from the nozzle impinges upon the surface of the ingot at the exit end of the mold from which the ingot emerges. Thus, the ingot is further cooled with the coolant delivered through the nozzle.
As an alternative to the horizontal continuous casting method using the stationary casting mold discussed above, roll-casting methods using cooling rolls are also available for continuously casting a flat ingot, particularly a thin strip. For example, Hunter casting and 3C-casting (Continuous Casting between Cylinders) are well known as roll-casting methods. In the roll-casting system, two cooling rolls are disposed in a vertically spaced-apart relation with each other, and the molten metal fed from a tundish is directed through a gap between the cooling rolls so that the melt mass contacting the cooling rolls is solidified into a solid strip. Thus, the solid strip is continuously cast.